Manufacture of telegraph-cables



(No Model.)

W. R. PATTERSON.

MANUFACTURE OF TELEGRAPH GABLES.

Patented May 13, 1890.

UNITED STATES WILLIAM R. PATTERS or CHICAGO, ILLINoIs.

MANUFACTURE OF TELEGRAPH-CABLES.

SPECIFICATION forming part of Letters Patent No. 428,055, dated May 13, 1890.

Application filed May 14, 1889. Serial No. 310,751. (No model.)

To all whom, it may concern:

Be it known that I, \VILLIAM R. PATTER- SON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in the h [anufacture of Telegraph-Cables, (Case No. 80,) of which the following is a full, clear, concise, and exact de scription, reference being had to the accompanying drawing, forn'iing a part of this specification.

My invention relates to the manufacture of electric cables, and its object is to reduce the static capacity of such cables and at the same time provide for readily removing the core or the greater portion thereof when ever such removal from the inclosing-pipe may be desired.

lleretofore cables having the core of insulated conductors protected by a pipe or sheathing of lead have been filled-that is to say, the space 01' interstices between the pipe and the core have been filled in various ways with various substances and by various processes.

As to the prior state of the art reference is made to United States Letters Patent granted me, as follows: No. 248,209, dated October 11, 1881, for method of filling telegraph-cables with insulating substances; No. 27 3,592, dated March 6, 1883,1'01 method of fillingtelegraphcables with insulating substances; No. 284,226, dated September 4, 1883, for apparatus for fillin g cables with insulati n g substances; and No. 378,175, dated February 21, 1888, for telegraph-cable.

My invention herein. consists in placing the core of insulated conductors deprived of moisture Within the pipe and then forcinginsulating-filling into both ends of the pipe. I consider a core consisting of insulated con- 'ductors thus deprived of moisture as an unsaturated core as distinguished from such a core which has been dipped in some melted insulating substance-ms, for example, hot paraftineso as to saturate the fibrous insulating-covering of the wires. In connection with this process I use, preferably, a generator of carbon dioxide and a charging-chamber containing the insulatingfilling operating upon the general plan of the apparatus de scribed in my said patent of September 4, 1883. This apparatus is, however, so constructed as to permit of forcing gas into the cable under a definite pressure and afterward forcing the insulating-filling into the two ends of the pipe under agreater pressure, as would be necessary. The gas within the pipe is thus compressed according to the distance to which the insulating-filling is forced in. The pressure of gas is produced in the usual way by allowing the sulphuric acid to flow into the chamber containing marble-dust or bicarbonate of soda. When thepressure reaches any desired limit, as shown by a gage, the gas is allowed to pass into the cable-pipe. The connection between the gas-reservoir and the cable-pipe is then closed and the other connect-ion between the melted insulated material and the cable-pipe is opened. More gas is then produced in the generator, as before, and the pressure allowed to rise high enough to force the melted insulating material into the ends of the pipe, and thereby still further to compress the gas which had previously been admitted. I therefore preferably provide a cock upon each end of the section of cable pvliicll is to be protected, these two cocks being connected with a common pipe leading to the charging-chamber and there branching, each branch containing a cook or valve, and one branch extending down into the ii'isulatingfilling and the other branch extending only into the upper portion'of the chamber containing the Thus by manipulating the valves and observing a gage the flow of gas and its pressure and the flow of the melted paratfine or other insulating substance may be regulated and controlled.

III the accompanying drawing I have illustrated suitable apparatus for carrying out my method or process, it being understood that I do not limit my patent to any particular apparatus or combination of devices for doing the work.

The coil of pipe (0 may be of any desired length. It is connected atits different ends with the reservoir Z), containing the melted paraffine and gas under pressure. The cocks 0 cl are both opened when the coil is being filled. First the gas cocl: c will, be opened and the paraffinecock f closed. The gas is then generated in the generator 9 at such pressure is required. A pressure from seventy to eighty pounds to the square inch IOC I have found sufficient. The gas-cock c remaining open the coil of pipe a will be filled with the gas and the air contained therein under the desired amount of compression. This is accomplished by shutting off the gascock e and opening the parat'tine-cock f, and still further increasing the pressure-say up to ninety or one hundred pounds per square inch. The necessary increase of pressure will vary in each individual case, according to the length of the cable which is being filled. The additional pressure necessary to force the parafline the requisite distance into the ends of the cable which is being filled depends upon the length of said cable, and is therefore necessarily determined independently in each case. In practice I fill the ends to a distance of about twenty-five feet each, regardless of the length of the cable, whether itis twohundred feetlongorathousand. After sufficient parafline has been forced into the pipe the cocks c (I are closed and the parafiine allowed to cool. The reservoir h is designed for supplying the tank with paraftine. I have shown the core at i bared, the lead pipe being .cut away for a short distance.

The gas, as is well understood, is generated in the generator g, and is conducted therefrom into the reservoir f containing the melted paraftine. This tank isnotcompletely filled with paraiiine, and hence the gas will rise to the top of the tank, and thus when the paraftine-cock f is closed and the gas-cock 0 opened the gas will be forced from the res ervoirf through the open cock c into the pipe (1, as before described.

The pipe or cable a, we will say, is a coil fourhundred feetlong. The core of insulated wires having been drawn into the pipe, it is desired to fill the space about the core for, say, twenty-five feet at each end of the section. The pipe being of lead is of sufficient strength to stand considerable pressure from within.

In order that the static capacity of the cable may be as low as possible, I avoid the use of a liquid or plastic insulatingsubstance in and about the core as far as possible. A

filling of some kind to actasa dam to prevent water from running longitudinally in the pipe I have found necessary at the man-holes where cables are laid under ground, since the pipe is so liable to mechanical injury at the man-holes. A short section of filling at the man-holes I have found, however, sufficient, especially where the core is protected by a lead pipe which has been tested by pneumatic or hydraulic pressure from within. The cablethat is to say, each section a of the cable I therefore fill at each end a short distance with insulating substance, the gas or air, or combination of gases in the pipe being compressed between the insulating-fillings at the two ends. The parafline or other insulatingfilling is forced in hot, after which itis allowed to cool before the pressure is removed, so as to hold the gas or air under pressure.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The method of manufacturing electric cables, which consists in forcing insulatingfilling into both ends of a section thereof, and thereby compressing the gas or air between said fillings, substantially as described.

9. The method of manufacturing telegraphcables, which consists in drying the core of insulated conductors, drawing the same unsaturated into the pipe, forcing an insulatingfilling into the two ends of the pipe, and thereby compressing the or air between said fillings, substantially as and for thepurpose specified.

33. The method which consists in first draw ing the dry unsaturated core into the cable and then forcing an insulating-filliug while melted into the ends of the pipe and allowing the insulatingfilling thus forced into the ends of the pipe to solidify, thereby holding the atmosphere between the fillings compressed, substantially as described.

4. The method of manufacturing telegraphcables, which consists in drying the core of insulated conductors, drawing the same unsaturated into the pipe, forcing gas or air into the pipe and then forcing melted insulating-filling into the two ends of the pipe, allowing the insulating-filling to solidify before the pressure is removed, whereby the gas or air is held under pressure, the core being left dry and unsaturated between the fillings, substantially as described.

In witness whereof I hereunto subscribe my name this lith day of May, A. D. 1889.

\VILLIAM R. PATTERSON.

Witnesses:

GEORGE P. BARTON, ELLA EDLER.

ICO 

